In early wagering in Las Vegas for the May 2 showdown between Manny Pacquiao and Floyd Mayweather Jr., Pacquiao has been the popular choice. “It’s been kind of surprising,” Jay Rood, vice president of race and sports books for MGM Resorts International, said on Thursday. Rood said the MGM has written 3½ times the number of bets for Pacquiao, than they have for Mayweather.